This disclosure relates to the connection of a mower cutting deck to the frame of a vehicle, and more specifically, to a suspension mechanism that provides and maintains that connection while using a minimal amount of hardware.
A variety of suspension mechanisms have been used to connect a mower cutting deck, and specifically its front portion, with the frame of a vehicle. This connection has been made by a linkage joining the front portion of the deck to the frame. In making this connection, the linkage has been received by a pair of brackets wherein one of which has been provided on the deck""s front portion and the other of which has been provided on the vehicle frame.
In considering the design and operation of at least one of these mechanisms, it has been observed that the above-mentioned linkage has a tendency to become disconnected from one or both of the brackets. This has happened as the vehicle is operated over rough ground surfaces. To reduce the possibility of disconnection, this mechanism has further included a member secured to the frame to block movement of the linkage. Because movement of the linkage is blocked, connection of the deck to the frame has been maintained.
When the above mechanism is used however, the initial expense of the vehicle is increased as are its maintenance costs resulting from any necessary replacement of the hardware. An example of a design having the above hardware may be found in U.S. Pat. No. 5,937,625 to Seegert.
Accordingly, there is provided a suspension mechanism which retains connection of the deck with the frame even when the deck is operated over rough ground surfaces. Further, this mechanism retains that connection with a reduced number of parts when compared with prior suspension mechanisms. As a result, the cost of the mechanism and the vehicle to which the deck is attached are each decreased.
The mechanism suspends a mower cutting deck beneath the mid-portion of a vehicle, optionally provided as a lawn and garden tractor. To do so, the mechanism includes first and second linkages which allow that suspension. The first, or front, linkage supports the front portion of the deck from the frame. The second, or rear, linkage supports the rear portion of the deck from the frame.
As stated before, the front linkage connects the front portion of the deck with the tractor frame. To do this, the front linkage includes a straightened end or rod portion having threads thereon and a connected angular portion which is non-threaded.
The non-threaded end is releasably received in a bracket attached to the deck. The threaded end is received by, or in, a channel formed in a retention member, preferably consisting of a further bracket, that is fixedly attached to the tractor frame. A ball member and nut are attached to the threaded end, each of which is also received by the channel to enable connection of the deck with the frame.
The ball member abuts against a spherical socket portion of the retention member for permitting the linkage to pivot in response to the contour of the ground surface. The nut is tightened against the ball member to cause the ball member to bear against the spherical surface and thereby place the linkage in tension. Distribution of this tension force substantially prevents the linkage from disengaging from the retention member. Further, this tensioning assists in positioning the deck relative to the ground surface.
The channel of the retention member includes an enlarged top end or portion in order to receive the rod, the ball member and the nut when connecting the deck to the frame. After insertion within the top portion, the rod is moved through a middle or throat portion which shifts laterally of the centerline of the top portion of the channel. The throat portion then leads downwardly to a bottom portion which is smaller in size than the top portion of the channel. The smaller dimension(s) of this bottom portion permits the rod portion, along with its ball member, to become fully and firmly seated therein when the rod is placed in full tension. As a result, connection of the deck to the frame may be firmly established.
Because of its lateral shift, the throat portion provides a path along which the rod travels when it is moved between the top and bottom portions of the channel. At times of inadvertent vertical movement of the linkage from the bottom, smaller portion of the channel (as may be possible when the tractor is operated over rough ground surfaces), the rod will abut a surface of the retention member along this path. This surface provides a stop or abutment which limits vertical travel of the linkage beyond the stop. Thus, the likelihood of unintended movement of the rod from the bottom end portion to the larger top end portion, and thereafter out of the channel, is decreased. Accordingly, the deck may be prevented from becoming disconnected from the tractor frame without the need for additional hardware previously used solely in blocking movement of the linkage.